Resilient wheel



A. BOSCHI RESILIENT WHEEL June 23, 1953 3 Sheets-Sheet l Filed Feb. 17,1948 An'ronio Boschi.

June 23, 1953 A. BOSCHI 2,643,153

RESILIENT WHEEL Filed Feb. 17. 1948 5 Sheets-Sheet 2 3 u. -H An'ronioBoschi June 23, 1953 A. BoscHl RESILIENT WHEEL 3 Sheets-Sheet 3 FiledFeb. 17, 1948 w Ahornevs Patented June 23, 195,3

RESILIENT WHEEL Antonio Boschi, Milan, Italy, assignor to SocietaApplicazioni Gomma Antivibranti, Milan, Italy Application February 17,1948, Serial No. 8,928 In Italy February 2 8, 1947 4 Claims. (Cl.295i-11) This invention pertains to elastic wheels for vehicles and moreparticularly has reference to antivibration wheels for railroad andtrainway cars on which the brakes are applied to the rims f the wheels.

In railroad and trainway wheels Where rubber cushioning elements areinserted in the web of the wheel between the hub and rim, in order toreduce shock, vibration and noise in operation, difficulty has beenencountered from the injurious effect on the rubber by the heatgenerated Vby the friction of the brakes on the rims. In order toprotect the rubber parts of these wheels from such damage, it isessential to provide means for minimizing the flow of heat from the rimsto the webs and for effectively dissipating the heat from the webs andparts of the wheel adjacent thereto, and particularly from the rubberelements.

In the prior art various expedients have been employed for this purpose,among which may be mentioned the use of heat-insulating materialsbetween the metal and rubber parts of the wheel; reducing the areas ofcontact between the rubber and heated metal elements; and centrifugalaeration of the heated parts of the wheel by air currents generated inthe rotation of the wheel by special more or less intricate Ventilatingchannels constructed in the body of the Wheel. While these variousexpedients have been helpful, they are difficult and expensive to applyand have not been altogether satisfactory in use.

An object of this invention is to secure better results than thoseobtained in the prior art, in a simpler and less expensive manner, bythe novel constructions and arrangements hereinafter described whichpermit the elastic elements of a wheel and the rigid metal plates towhich they are bonded to have almost their whole external surfacesexposed to direct contact with the circumambient air, whereby themaximum cooling of these parts is attained through direct radiation ofheat to the air.

Another object of this invention is to reduce to a minimum the surfaceof contact between the rim and adjacent parts of a wheel, therebyreducing the amount of heat which can be transmitted by conduction fromthe rim to the rubber elements.

A further object of this invention is to devise means to propercentering of the rigid annular members of the assembled elastic web tothe rim and hub of the wheel by coasting channels in the fiange of therim and hub.

Still another object of this invention is to 'provide in the rubberelements of anelastic various parts of the wheel and improvement inV itstransverse stability.

With these and other objects in view which: may be incident to myimprovements, my invenl tion consists of the combination and arrangementof elements hereinafter described and illus-y trated in the accompanyingdrawings in which the same reference numerals refer to correspondingparts in the several figures and in Which:

Figure 1 is a partial side elevation of an elastic wheel according to myinvention in which a portion of the rim and hub is shown in longitudinalsection,

Figure 2 is a radial section of the wheel shown in Figure l,

Figure 3 is a fragmentary cross-section of the web of the wheel shown inFigure 1, on a plane parallel to the axis of rotation,

Figure 4 is a view, similar to Figure 1, of a modified form of myinvention,

Figure 5 is a radial section of the wheel shown in Figure 4,

Figure 6 is a fragmentary cross-section of tlie web of the Wheel shownin Figure 3, on a plane parallei to the axis of rotation.

Figure '7 is a view, similar to Figure 1, of another modication of myinvention,

Figure 8 is a radial section of the Wheel shown in Figure 7, and

Figure 9 is a fragmentary cross-section of the web of the wheel ,shownin Figure 7, on a plane parallel to the axis of rotation.

Referring to Figures 1, 2 and 3 of the drawings, the reference numeral ldenotes the rim of a wheel, 2 the hub, and 3 the assembled web whichconnects the rim to the hub. The rim l has a tread i which contacts theupper face of the rail and an outwardly extending fiange 5` whichcontacts the inner face of the rail. Thev brake shoe (not shown) for thewheel generally contacts the surface of tread 4, although by propercontouring, the shoe may also engage the inner face of flange 5 when thebrake is applied.. The rim I has 'two inwardly-projecting, rigid,circumferential anges 6 which are provided with a number of spacedtransverse holes 1 for the reception of bolts 8 with lock nuts 9, asclearlyA shown inA Figure 2. The flanges 6 also have undercut` channelsl0 and Il on their inner and. outer faces vrespectively which serve forthe reception of matching circular ribs on inner and Extending radiallyfrom the hub 2 is a rigid,V

integral annular flange I9 which is provided with a number of transverseholee 2,0 of such site as to permit free passage of the sleeves I8thrqugh the ange I3 without any contact therebetween, as clearly shownin Figure 2. Each side face of the iiange I9 has a circular groove forthe rea ception of matching circular plates 2| and 22, each of which isbonded to an elastic '(rubber) disc 23 and 24. Each disc 23 and 24 is inturn bonded to an outer circular plate 25 and 2B which fits into amatching circular groove in web members I2 and I3 respectively. When thenuts I'I are tightened on the bolts I6, the rubber discs 23 and 2d aresqueezed into initial compression during assembly of the webl 3 to therim I and the hub 2. This compression is facilitated by a series orradial channels 21 which are provided in both rubber discs 23 and 24 atclosely spaced intervals and which also serve to cool the rubber bycentrifugal air flow therethrough when the wheel is in rotation. Radialchannels 2l are spa-ced in each disc in staggered relation to each otherso as not to coincide in any one radial plane, as indicated in Figures 2and 3, thereby increasing their heat dissipating capacities.

To further facilitate the radiation of heat from the rubber discs 23 and24, each web member I2 and I3 has a number of closely spaced radialcut-away portions or spaces 28V, of such width as to leave therebetweenan equal number of` radial spokes 29 of generally ellipticalcrosssection, shown in Figure 3. The rounded contour or' the spokes 29affords a minimum area of contact between each spoke and the adjacentplates 25 and 2 5, thereby reducing to a minimum the flow of heat fromthe rim through the web members I2 Yand I3 to the rubber discs 23 and24. The cut-away portions 28 in each web member I2 and I3 are alsostaggered with relation to each other, so that each space 28 in the webmember I2 falls opposite a spoke 29 in the web member I3, therebyincreasing the lateral stability of the wheel.

1t will be apparent from the foregoing description that the radialthrust from the hub 2 to the rim I, and the tangential thrust from therim i to the hub 2 will be transmitted through the web 3 by simpleshear-flexion of the rubber discs 23 and 24 with respect to their bondedplates 2 I, 22, 25 and 26, since the inner plates 2| and 22 are firmlyembedded in circular grooves in flange I9 and the outer plates 25 and 26are similarly fixed to the web members I2 and I3, and since the rlangeI9 is integral with the hub 2 and the web members I2 and I3 are lockedto the rim I. Also, the holes 2G in the flange I9 are of such large sizewith reference to the sleeves I8 that there is no VContact therebetween,even when the wheel is loaded, so that the only way in which a thrustfrom the rim I can reach the hub 2 and vice versa is through the rubberdiscs 23 and 2 4 and such thrust produces sheareflexion stresses inthese discs.

The areas of contact between the rubber discs `23 and 24 which arebonded to the plates 2 I, 25,

22 and 26, are such as to elastically resist the full load radial thrustof the hub 2 on the rim I, as well as the maximum tangential breakingthrust of the rim to the hub.

Furthermore the hereinbefore mentioned axial precompression of therubber discs assures the lateral `stability of the wheel. The channels21 facilitate also said initial compression, reducing the maximum stresscaused thereby, and permit great compression resistant to any tensionalaxial stress due to railway irregularity, curves, etc. At the same timeall shocks and vibrations from the rim are absorbed by the rub- 'ber`discs before they reach the hub, since there is no direct metal-to-metalconnection between the rim and hub.

The proper centering of the web members I2 and I3 with respect to therim I is secured by the interlocking Iconnections between the annularprojections around the outer edges o the web members I2 and i3 andco-acting channels in the ange fi of the rim. This interlockingconnection also prevents the rim and web members from having differentradial and tangential expansions with changes in temperature, therebypreserving the rotational concentricity of 'the wheel.

1n order to further reduce the flow of heat by conduction from the rimto the' webI members I2 and I3, the latter are provided near theirperipheries with a series of cut-away notches 30 which reduces the areaof contact between the rim and web members. The remaining intermediateportions of the peripheries between the notches may be considered in thenature of stub spokes adapted to engage the rim. To afford an electricalconnection between the hub 2 and the rim I, there is provided a flexibleconductor 3| which is clamped between the head of the bolt le and theweb member I2 at one end and attached at its other end to the hub 2 by ascrew 32.

It will be apparent from the foregoing description that by means ofcut-away areas 2@ in both web members l2 and I3, the spaces left betweenboth ends or the rubber discs 23 and 2,2, and the holes 2i] in theiiange I3, there is provision for the maximum exposure oi' the plates4bonded to the rubber discs and the discs themselves to the surroundingair, thus insuring the maximum heat loss in the rubber discs 23 and 24by direct radiation. These means of cooling the discs 23 and 24 havebeen augmented by providing the radial channels 2'! in these discs, soas to insure air flow` therethrough from centrifugal aeration duringrotation of the wheel.

Referring to Figures e, 5 and 6 of the drawings, it will be noted thatthe modifications shown in these figures differs from the form of wheelshown in Figures l, 2 and 3 principally in the reversal of thearrangement of the inner and outer web members I2 and I3 and the cen-=tral flange I9, with respect to the rim I and the hub 2. Here the inner'web member I2 is integral with the hub 2 and the central flange I9 isintegral with the rim I. The outer web member I3 is bolted to an annulariange 33 on the hub 2 by means of inner bolts it, while the web membersI2 and I3 are tied together by the outer bolts 8 and the spacers I8which pass through the holes 2G in the frange I9, and also through the'holes 34 and 35 in the rubber discs 23 and 24.

The cut-away portions 28 in the web members I2 and I3 of the wheel shownin Figures 4, 5 and 6 are much smaller and fewer in number than those inthe wheel shown in Figures 1, 2 and 3, so that the intervening metalportions 29 in Figures 4, 5 and 6 are in the nature of circularsegments, instead of rounded spokes as in Figures 1, 2 and 3. Thisconstruction of the web members I2 and i3 makes them better adapted tobe fabricated from forged steel plates, with the cut-away portions 28removed by milling, whereas in the wheel shown in Figures l, 2 and 3,the web members I2 and I3 are most easily made by casting the metal inthe form depicted.

In the form of wheel shown in Figures 4, 5 and 6, the inner plates 2land 22, which are bonded to the inner faces of the rubber discs 23 and24, are provided with a series of spaced circular grooves 35interconnected by a number of radial grooves 3l, as shown in Figure 4.These grooves reduce the area of metal-to-metal contact between theplates 2l and 22 and the central flange i9, and thus serve to diminishthe amount of heat liowing by conduction fromv the rim I through theilange I9 to the rubber discs 23 and 24. Also the radial grooves 3?promote the centrifugal circulation of cooling air through the grooves35 when the wheel is in rotation, thus ali'ording additional means ofkeeping the rubber discs within permissible temperature limits at alltimes.

In the further modification of my invention illustrated in Figures '7, 8and 9, the wheel is very similar in construction to that form shown inFigures 4, 5 and 6, the principal difference in these two forms being asfollows. In the wheel depicted in Figures '7, 8 and 9, the cut-awayportions 28 in the inner and outer web members I2 and I3 are reduced tovery small holes 28 located near the hub 2, as shown in Figure '7. Thisleaves the web portion 29 of the members I2 and i3 as an almost solidcircular plate which adds to the lateral strength of the wheel butreduces the area of the plates and 28 exposed to the surrounding air'and therefore the cooling effect on the rubber discs 23 and 24.

Also in the form of wheel shown in Figures '7, 8 and 9, there are nogrooves in the inner plates 2l and 22, as in the form shown in Figures4, 5 and 6, but in lieu thereof are provided radial grooves 33 in thecentral iiange I9. These grooves are obtained by giving the centralflange a wavy contour as shown in Figure 9 and the grooves 38 vary inwidth from a minimum near the hub to a maximum` near the flange, asclearly illustrated in Figure '7. By this means a rapid circulation ofcooling air is obtained through the grooves 38 by centrifugal force whenthe wheel is in rotation.

A comparison of the three forms of wheel illustrated in the drawingsshows that the wheel depicted in Figures 1, 2 and 3 aflords the largestcooling efect on the rubber discs from circumambient air and the leastlateral strength, and the wheel shown in Figures 7, 8 and 9 affords theleast cooling eifect on the rubber discs but maximum strength of wheel,while the form shown in Figures 4, 5 and V6 is intermediate between theother two in both of these respects.

While I have shown and described the preferred forms of my invention, Idesire it to be understood that I do not limit myself to theconstructional details disclosed by way of illustration, as it isapparent that these may be changed and modified by those skilled in theart without departing from the spirit of my invention or exceeding thescope of the appended claims.

I claim:

1. An elastic wheel having a rigid hub and rim and a resilient webconnecting said hub and rim, said web comprising a plurality of rigidannular members radially attached alternately to said hub and rim, andan elastic disc interposed between each adjacent pair of said rigidmembers and adapted to transmit thrust from said hub to said rim byshear-flexion stress, the outer rigid annular members having relativelylarge out away portions axially opposite the side faces of the nextadjacent elastic disc, thus exposing substantial areas of said discs tothe surrounding air, and dening radial spokes in said outer annularmembers which, upon rotation of the wheel, serve as fan blades toincrease the circulation of said air across said exposed areas, andthereby increase the radiation of heat from said elastic discs.

2. A wheel according to claim 1, in which cutaway notches are providedin the outer peripheries of said outer members to reduce the conductionof heat from said rim to said outer members.

3. A Wheel according to claim 1, in which said notches are of suchrelatively large size that the walls of said rigid outer members betweensaid notches constitutes stub spokes, the outer ends of which engagesaid rim.

4. An elastic wheel having a rigid hub and rim and a resilient webmember connecting said hub and rim, said web member comprising aplurality o-f rigid annular members radially attached alternately tosaid hub and rim, and an elastic disc interposed between each adjacentpair of said rigid members and adapted to transmit thrust from said 'hubto said rim by shearflexion stress, the outer rigid annular membershaving, in locations opposite the side faces of the next adjacentelastic disc, relatively large openings, with their lengthwisedimensions extending radially so that the Wall of each said outer rigidannular member between adjacent openings constitutes radial spokes.

ANTONIO BOSCHI.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,122,620 Madden Dec. 29, 1914 2,244,633 Saurer June 3, 19412,278,711 Piron Apr. 7, 1942 2,294,818 Williams Sept. 1, 1942 2,295,269Piron Sept. 8, 1942 2,295,270 Piron Sept 8, 1942 2,310,486 ZintsmaterFeb. 9, 1943 FOREIGN PATENTS Number Country Date 390,953 Great BritainApr. 20, 1933

